The invention relates to laryngeal masks, illustratively of varieties disclosed in U.S. Pat. Nos. 4,509,514 and 4,995,388, and in U.K. Patent No. 2,205,499. Such masks are artificial airway devices to facilitate lung ventilation in an unconscious patient. More specifically, the invention pertains to such a device designed for placement in the pharynx of the patient in order to prevent airway obstruction and to permit either spontaneous or controlled ventilation.
U.K. Patent No. 2,205,499 describes a flexible web closing the rear of the lumen of the mask and providing a pocket having a transverse slit opening toward the aperture of the airway tube, for receiving the end of a substantially rigid introducing tool. This pocket is effective when used with the introducing tool; however, it may act as a dirt-trap since secretions or blood may lodge in the pocket and thereby escape sterilization. The introducing tool may be required to elevate the epiglottis after inserting the mask, since insertion may push the epiglottis into a down-folded position, causing partial airway obstruction.